Vessels used on water are steered in any of a variety of ways. One way, commonly used on seagoing vessels and on larger pleasure craft, is to have one, two or more "screws" or propellers turned by shafts, the orientations of which remain unchanged with respect to the vessel hull. Steering is by a separate rudder.
Another way commonly used with smaller pleasure craft is to pivot all or a part of the propulsion system so that the rotational axis of the propeller moves with respect to the vessel hull. On so-called inboard-outboard drives, only a portion of the propeller drive train pivots. However, on boats driven by outboard engines, the entire engine (but for its mounting bracket and the like) are pivoted on the rear transom of the boat. The invention relates to boats of this latter type and, particularly, relates to an apparatus for steering an outboard engine.
Smaller outboard engines are steered by an operator sitting at the rearmost seat and grasping the engine handle. Such handle not only pivots the engine about a generally vertical axis, it usually includes a twist-type throttle control. Thus, the operator controls vessel speed and direction with one hand.
For larger outboard engines, hand steering in the aforementioned manner is impractical. For one thing, the engine is simply too heavy to steer with one hand. And boats large enough to accept such an engine usually have steering and throttle controls at a forward seat location. The operator faces directly forward as when driving an automobile.
Larger outboard engines are often steered using some type of "force-multiplying" mechanism such as a steering wheel and control cable, the latter as made by Morse Controls and others. Or steering may be by hydraulic cylinder. In a common arrangement, the cylinder body is mounted in a fixed location and a cylinder rod is coupled to the engine tiller bar by a steering link. In another arrangement, the rods are at a fixed location and the cylinder body is coupled to the tiller bar for bar movement.
When a hydraulic cylinder is used, such cylinders are "double-ended" in that a cylinder rod protrudes from each end of the cylinder. A double-ended cylinder has equal areas under pressure for either steering direction and the control, e.g., the steering wheel, behaves symmetrically. In order to provide such function, "prior art" cylinders have a single connection, i.e., a pressure fitting, for each hydraulic line connected to the cylinder. Each such fitting connects directly to a separate chamber at each end of the cylinder piston.
When a cylinder is installed (as new or replacement equipment), the installer must use each pressure fitting alternately as a pressure inlet port and as a bleed port to exhaust air from the circuit. To say the least, this is quite time consuming--it is not uncommon for an hour or more to be required to install a steering cylinder.
Yet another disadvantage of certain known outboard engine steering cylinders is that the fittings are placed on the front face of the cylinder body and project toward the bow of the boat when the engine is in propulsion position. In certain other prior art embodiments, the fittings are positioned on the cylinder top surface and project upward from the cylinder. When the engine is tilted upward or moved from side to side, such fittings can become jammed into structural portions of the boat or the engine. Boat and/or fitting damage often results.
U.S. Pat. No. 5,149,285 (Kinoshita) shows an outboard engine arranged for tilting. The way in which fittings can become jammed will be apparent from an inspection of the Kinoshita patent.
Still another disadvantage of known outboard engine steering cylinders is that they or their mounting brackets are configured to fit but a single "brand" of outboard engine. Thus, the manufacturer is required to produce hardware in a variety of configurations, increasing manufactured costs. And if the distributor resolves to provide prompt service, such distributor must stock the same variety of configurations. Higher inventory and handling costs inevitably result.
An improved steering cylinder for outboard engines which addresses disadvantages of earlier steering cylinders would be an important advance in the art.